IṢẸ́ ỌNÀ
ẸWÀ ÀTI ÌLERA
IṢẸ́ ỌWỌ́
ÀṢÀ ÀTI ÌTÀN
ÌṢERÉ
ÀYÍKÁ
OÚNJẸ ÀTI OHUN MÍMU
REVERSE ENGINEERING
SÁYẸ́ǸSÌ
ERÉ ÌDÁRAYÁ
ÌMỌ̀-Ẹ̀RỌ
ÀWỌN OHUN WÍWỌ̀
Opacity and Tinting Strength: Why Some Colours Go Ten Times Further
Two paints of the same colour can behave completely differently in a mixture: one overwhelms everything it touches, the other disappears. That is TINTING STRENGTH, and it is not the same thing as opacity.
OPACITY is how well a paint hides what is underneath it. It comes from the difference in refractive index between the pigment particles and the binder around them — the bigger that difference, the more light is scattered and the less gets through.
Which explains something that puzzles everyone at first: a pigment can be intensely coloured and nearly transparent, or pale and completely opaque. Ultramarine and titanium white are opposite extremes of exactly this, and knowing which you have is what makes glazing and mixing predictable.
Àárín
3 hours
Ìlànà
1
1
Refractive index is what makes a pigment opaque
Refractive index is what makes a pigment opaque
Ń ṣí ìwé Jupyter…
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àkójọ Ẹ̀kù Awọ̀ Ilẹ̀1 ẹyọ
Òróró Ọ̀gbọ̀1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Kọ̀ǹpútà Tábìlì
Ọmọ Odó Gílásì
Lúpù Ìgbéga2
2
Make a transparency chart and keep it
Make a transparency chart and keep it
Draw a thick black line across a white card, then paint a band of every colour you own across it, in one consistent thickness. Where the line shows through, that paint is transparent.
Label each band and keep the card. It answers, instantly and for your actual paints, the question that decides whether a colour can be glazed, whether it will cover an underpainting, and how it will behave in a mixture.
Do it again for any new brand. Two tubes labelled the same colour from different makers can differ enormously in pigment load and therefore in both opacity and tinting strength — the label names the pigment, not the formulation.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àkójọ Ẹ̀kù Awọ̀ Ilẹ̀1 ẹyọÒróró Ọ̀gbọ̀1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ìṣù bùrọ́ọ̀ṣì oníṣẹ́-ọnà
Ìdíwọ̀n3
3
Glazing and scumbling use the two ends of the range
Glazing and scumbling use the two ends of the range
A GLAZE is a transparent dark colour over a lighter layer. Light passes through it, reflects off the layer beneath and comes back through — so the colour is produced by light that has travelled through the paint twice, which gives a depth no opaque mixture reproduces.
A SCUMBLE is the opposite: a thin, broken, semi-opaque light colour dragged over a darker one. The result is optical rather than mixed, and it is how skies and flesh have been painted for four hundred years.
Both fail with the wrong pigment. A glaze in titanium white is a pale opaque smear; a scumble in ultramarine disappears. Choosing the pigment for its optical behaviour, rather than only its hue, is what makes either technique work.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àkójọ Ẹ̀kù Awọ̀ Ilẹ̀1 ẹyọÒróró Ọ̀gbọ̀1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ìṣù bùrọ́ọ̀ṣì oníṣẹ́-ọnàLúpù ÌgbégaÌdíwọ̀n4
4
Particle size changes both, and it changes with grinding
Particle size changes both, and it changes with grinding
Scattering is strongest when the particles are roughly half the wavelength of light — around 0.2 to 0.3 micrometres. Larger or smaller and a pigment scatters less, so opacity has an optimum rather than rising forever with fineness.
Which means grinding a pigment finer does not simply make it better. Natural ultramarine ground too fine becomes pale and grey, and the traditional coarse grind is not laziness — it is where the colour is.
It also means two jars of the 'same' pigment can behave differently because they were milled differently. That is a real variable, it is invisible on the label, and it is one more reason to test what you actually have rather than what the name promises.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àkójọ Ẹ̀kù Awọ̀ Ilẹ̀1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ọmọ Odó GílásìLúpù ÌgbégaBlueprint tó jọra
Àwọn blueprint wọ̀nyí pín ìmọ̀ — ọ̀nà, ohun-èlò tàbí ìlànà
What Paint Is: Pigment, Binder, and the Ratio Between Them
láti ọwọ́ Mary
Kẹ́míkà
21
0
0
0
0
0
Léwu
Making Lead White (Flake White) — The Dutch Stack Process for the Most Important Pigment in Oil Painting History
láti ọwọ́ Charlie
IṢẸ́ ỌNÀ
89
0
0
0
5
0
One Reading Is Not a Measurement: Repeat It, and Look at the Spread
láti ọwọ́ Penny
Ìmọ̀-ẹ̀rọ
36
0
0
0
0
0
CC0 Àgbègbè Gbogbogbò
Blueprint yìí ti jáde lábẹ́ CC0. O lè ṣe àdàkọ, yí padà, pín, àti lò láìsí ìyọ̀ǹda.
Ṣàtìlẹ́yìn Olùṣẹ́dá nípa rírà àwọn ọjà nipasẹ̀ Blueprint wọn Ẹ̀san Olùṣẹ́dá tí àwọn Olùtajà gbé kalẹ̀, tàbí ṣẹ̀dá àtúnṣe tuntun ti Blueprint yìí kí o sì fi sínú Blueprint rẹ gẹ́gẹ́ bí ìsopọ̀ láti pín owó-wíwọlé.